1. Field
The present disclosure relates generally to the field of video data processing, and, more particularly, to a multi-panel rate control method for real-time digital video encoders such as an MPEG-4 or an H series encoder.
2. Related Art
Video signals generally include data corresponding to one or more video frames, where each video frame is composed of an array of picture elements (pels). A typical color video frame at standard resolution can be composed of over several hundred thousand pel arranged in an array of blocks. Since each pel has to be characterized with a color (or hue) and luminance characteristics, these data may be represented with groups of four luminance pel blocks and two chrominance pel blocks called macroblocks (MBs). Thus, digital signals representing a sequence of video frame data, usually containing many video frames, have a large number of bits. However, the available storage space and bandwidth for transmitting such signals is limited. Therefore, compression processes are used to more efficiently transmit or store video data.
Compression of digital video signals for transmission or for storage has become widely practiced in a variety of contexts, especially in multimedia environments for video conferencing, video games, Internet image transmissions, digital TV and the like. Coding and decoding are accomplished with coding processors which may be general computers, special hardware or multimedia boards and other suitable processing devices.
Compression processes typically involve quantization, in which sampled video signal data values are represented by a fixed number of redefined quantizer values. The quantized signal is composed of quantizer values that are approximations of the sampled video signal. Therefore, the encoding of the video signal data onto a limited number of quantizer values necessarily produces some loss in accuracy during the decoding process.